In 1989, the fall of the Berlin Wall became a striking symbol for free expression far beyond the borders of Germany. Just 20 years later, Iranian citizens used online tools like YouTube and Twitter to share firsthand accounts of the brutal government crackdown waged against protesters disputing the country's election results. Many Iranians risked their lives to document the violence, despite the government's attempts to expel journalists and stifle any voices of dissent.

The democratizing power of the Internet has enabled individuals to share their stories with a global audience in ways never before possible, and given a voice to those who wouldn't otherwise be heard.

This channel is designed to feature your stories and reflections on free expression. Tell us about how you or someone you know has taken a stand for free expression. Perhaps you've protested against something you didn't agree with, taken action when someone else's free speech was being suppressed or been inspired by someone who has stood up for the right to speak out. Make a short video sharing your experience, upload it to YouTube, and add it as a reply to this one:

We'll be featuring the best submissions on the Google Free Expression channel, so be sure to check back in the weeks to come. We look forward to hearing from you.

We are counting down the hours to this evening's U2 concert at the Rose Bowl stadium in Pasadena, CA. The live stream begins at 8:30 p.m. Pacific Time (3.30 a.m. GMT), and YouTube users all around the world can tune in. (To figure out what time the concert starts where you are, simply click the time converter here and select the name of your country in the pull-down menu.)

Once the show starts, scroll down on U2's channel for a Twitter gadget displaying real-time comments about the webcast. If you Tweet from this tool, you'll see that each message is pre-populated with the hashtag #U2webcast, instantly plugging your comments into wider discussions about the show.

For those of you who miss the live event, the full performance will be re-broadcast two consecutive times after it ends. It will also be archived as a video on the U2 channel -- so there's really no excuse to miss Bono's distinctive wail, the Edge's guitar mastery, the roll of Larry Mullen's drums, or Adam Clayton's thumping bass lines. Let this preview whet your appetite for the experience up ahead...

As climate change campaigns go, What’s Funny About 1,431 takes a slightly different tack to many but shares the same message: you can make a difference and you can do it today in many, many simple ways. The kicker being that these efforts can also save you money in the process – up to £1,431 a year.

The people behind the programme, Together.com, are using comedy and YouTube to help get the word out. They have challenged 10 comedians to come up with their take on the number 1,431 and are asking viewers to vote for their favourite. If you back the winner, you will be in with a chance to win £1,431… and if you can impress the panel with your take on their power number, you’ll be in line for a similar amount.

YouTube UK’s BenLoka has already leant his support to the programme, sparking an interesting debate on vegetarianism in the process, so head over to WhatsFunnyAbout1431 and learn more. As for us, we’re off to stock up on energy saving lightbulbs (saving up to £37 a year in the process).

Today, Comments Search moves into Test Tube, the place where our engineers and developers test out new features and gather data and feedback before pushing them out to a wider audience. This feature allows you to search the comments people are making on YouTube in real time. The full comment will appear on a continuously updated results page, and "trending topics" indicates the hottest topics of conversation on YouTube at that particular moment. Comments Search is a way you can find out what YouTube users are saying about everything from the news stories of the day (below, see results when we typed in "balloon boy") to your individual channel or brand.

So try it out, enter your feedback here or comment below, and help us get this feature ready for the masses. We're always working on new ways to enhance search across YouTube and give quick and easy access to the information people are looking for.

If you are a fan of the Irish rock band U2, you may have already caught wind of a little secret. Earlier today, the band alerted fans that they will be able to watch their upcoming performance from the Rose Bowl in L.A. on their YouTube channel.

If you live in one of the 16 countries listed below*, you can join U2 live on Sunday, October 25 at 8:30 p.m. (Pacific Time). In addition with pumping your fist along with Bono, you'll be able to join YouTube's global listening party via a Twitter gadget embedded on U2's YouTube channel. And if you miss the concert, just press play when you wake up or get to a computer: the uploaded rebroadcast of the full show will be available the next day.

YouTube and Channel 4 have just signed a deal that will make the broadcaster’s programmes available on demand, in full and free-of-charge via YouTube in the UK.

As a result of the agreement Channel 4 will shortly begin to upload full-length shows to YouTube, building towards early 2010 when a full catalogue of catch-up TV as well as around 3,000 hours of archive programming will be available - including shows like Skins, Brass Eye, Teachers and Ramsay’s Kitchen Nightmares.

Channel 4 have enjoyed huge online support for their shows to date, and it’s exciting to think that they will be available on YouTube in full after screening on TV. Earlier this year the broadcaster invited YouTube users to audition for a place in the Big Brother House via YouTube, and there are plans afoot to involve the YouTube community in future Channel 4 initiatives. To be the first to know about these, keep an eye on the YouTube UK Blog.

YouTube's Creator's Corner and Videomaker magazine are excited to bring you the first in a series of Webinars that explore the basics of video production and will help you take your videos to the next level. Videomaker offers intensive weekend courses here in Northern California, and they've generously offered to share their knowledge with the global YouTube community for free, as well as take your questions.

The first seminar will focus on "Basic Shooting Techniques" and it's scheduled for October 27, 2009, at 2 p.m. PT / 5 p.m. ET. Click here to register.

Because we want these sessions to be really useful for you, we want you to help us set the agenda. Below is a list of topics the class could cover. Leave a comment at the bottom of this post to tell us which topic(s) you most want to know about. You can also submit and vote on specific questions here. We'll use your feedback as a guide when structuring the Webinar. Again, here are the topics:

Shopping for a camcorder: Learn what to look for before buying one

Button basics: Master the most important buttons on the camcorder and how each of them works

Light and filter it right: Creative tips on lights and filters that will improve the look of your videos

Microphone techniques: Get the best sound from your mic with the least amount of hassle

The art of composition: Simple composition rules to set your video apart from ordinary videos

Smooth moves: Handheld camera techniques

Finally, if you've got a strong preference for days of the week or times when you'd most likely be able to tune in to a Webinar, please let us know in the comments below, and we'll take that into consideration when planning future events.

This week we're joining in Google's celebration of all things mobile to make sure you're aware of the power you hold in your fingertips with YouTube on your phone. Not only can you watch millions of videos, but also you can upload videos directly from your device; maybe it's footage of a breaking news event, the drama unfolding at the party Saturday night, or your baby's first steps. Since we want to provide the best experience for each of you, we occasionally have different solutions for different phones -- so read on to find out what's available for yours.

Almost any phone with a browser can access the YouTube mobile website at m.youtube.co.uk. (Some mobile phone operators offer a pre-programmed link, so if a YouTube link displays on your phone, click it to visit our site.) Once there, you can access your YouTube account, your favourite videos, your uploads and your favourite channels. You can also share, rate, and comment directly from the mobile website to other YouTube users. Or, if you've captured a great moment, upload your own video by sending it via MMS or email (sign in to YouTube and click here to get your unique address) and it will appear almost instantly on the website.

In addition to the website, you can also play high-quality YouTube videos with special applications on many devices, including Windows Mobile, Symbian S60, iPhone, Android, Palm Pre, and BlackBerry Storm v1 devices. For devices not listed, it means that there were either technical limitations to getting YouTube on the phone, or the experience wasn't a significant improvement over just visiting the mobile website. FYI, the apps for iPhone, Android and Palm Pre also support direct-to-YouTube uploads. To install the app on a compatible phone, visit m.youtube.co.uk/app.

Keep an eye out this week as we tweet some useful tips and tricks for YouTube mobile. And be sure to let us know how you're liking it and what we can do to improve the mobile experience. To get started, just Go Mobile!

Three years ago today, Steve and I stood out in front of our offices and jokingly crowned ourselves the burger kings of media. We'd just made headlines by joining with Google in our shared goal of organizing the world's information (in our case, video) and making it easily and quickly accessible to anyone, anywhere. Today, I'm proud to say that we have been serving well over a billion views a day on YouTube. This is great moment in our short history and we owe it all to you.

Looking back at those early days, we were committed to some basic principles that have since become fundamental tenets in the world of online video:

Speed matters: Videos should load and play back quickly.

Clip culture is here to stay: Short clips are voraciously consumed and perfect for watching a wide variety of content.

Open platforms open up possibility: Content creation isn't our business; it's yours. We wanted to create a place where anyone with a video camera, a computer, and an Internet connection could share their life, art, and voice with the world, and in many cases make a living from doing so.

Three years after the acquisition, our platform and our business continue to grow and evolve. We are still committed to the same principles that informed the site early on, but we know things have changed. As bandwidth has increased, so has our video quality. As we've started to see demand for longer, full-length content, we've brought more shows and movies to the site. There are now more ways than ever to make and consume content, and more of you are looking to turn your hobby into a real business. We're working hard to keep up with the fast pace of technology to bring you everything you would expect from the world's largest video site: better quality; a full spectrum of choices and tools for users, partners and advertisers; and ways to make the YouTube experience your own anywhere, anytime.

A couple of weeks ago we quietly launched a new and easier way to share private videos: now you can generate a special URL for your private video and send it to up to 25 people, who, assuming they're logged in to YouTube, just have to click to view. This should make it a lot easier for your technology-challenged relatives to watch that video of baby's first steps without having to share it with the whole world.

A neat thing about this feature was that it was an outcome of a recent "hackday" here at YouTube. Hackdays are similar in spirit to "20% time" -- the amount of time in a week engineers at Google/YouTube are encouraged free think and innovate on projects they're passionate about. These efforts allow us to focus on launching smaller features that aren't on our official roadmaps but that we hope are still worthwhile for our users. Anyway, this hackday came with donuts, which were delicious and way too tempting for me to resist. I also had a strong personal motivation for figuring this out: I'm in a hip-hop dance group, and the troupe wanted to share practice videos without going through the process of becoming Friends on YouTube.

Even without any official announcement (until this post, that is!), uptake and usage of this feature has been strong. Here you can see the growth of private-videos-per-day using friend-to-friend sharing versus the new URL-sharing:

So test it out: go here and click on Edit on any one of your videos. Scroll down to "Broadcasting and Sharing Options," and you should see the privacy settings there. Click on Private to unlock the different ways of sharing the video, including the option to generate a limited-access URL. You can find out more about private videos in this Help Centre article.